The present invention relates to a new and distinct cultivar of chrysanthemum plant, botanically known as Chrysanthemum×morifolium Ramat., commercially known as a garden mum, and hereinafter referred to by the cultivar denomination ‘Zanmuday’. ‘Zanmuday’ is a product of a breeding and selection program for outdoor pot mums (garden mums) which had the objective of creating new cultivars with a double type inflorescence, a natural season flowering date around October 8 (week 41), blooming for a period of 5 weeks. ‘Zanmuday’ is a seedling resulting from a cross of the female parent id 24636 with the male parent id 26443. Plants of the new cultivar ‘Zanmuday’ differ from plants of the female parent in inflorescence size; the inflorescences of the seedling are larger than those of the female parent. Plants of the new cultivar ‘Zanmuday’ differ from plants of the male parent in natural-season flowering date; plants of the seedling flower in an earlier period than those of the male parent.
The new and distinct cultivar was discovered and selected as a flowering plant by Wilhelmus Bernardus Blom on a cultivated field in Rijsenhout, The Netherlands in 2007. The first act of asexual production of ‘Zanmuday’ was accomplished when vegetative cuttings from the initial selection in 2007 were propagated further in a controlled environment in Rijsenhout, The Netherlands. The new cultivar has been found to retain its distinctive characteristics through successive propagations.